A Hydrogen Bonded Organic Framework Constructed from Mixed Valence Fe Clusters for Efficient H₂O₂ Photosynthesis.

Abstract

A critical bottleneck in photocatalytic H₂O₂ production lies not only in the severe non-radiative energy losses incurred from enhancing light absorption, but also in a fundamental proton-electron kinetic imbalance. Here we introduce a light-heat-proton coupling strategy that harnesses the dissipated photothermal energy to activate proton dissociation from carboxylic acids, thereby creating a productive driving force for redox catalysis. A hydrogen-bonded organic framework (HOF-FJU-200) incorporating mixed-valence Fe²⁺/Fe³⁺ clusters is constructed via a metalloligand approach. The intervalence charge transfer transitions within these clusters generate strong photothermal conversion while extending light absorption to the NIR-II region ( ~ 2500 nm). The resulting thermal energy activates proton dissociation from unpaired carboxylic acid groups, synchronizing proton release with photoinduced electron transfer. This cooperative mechanism effectively channels non-radiative heat into catalytic function, achieving an H₂O₂ production rate of 10657 μmol·g^-1·h^-1 without sacrificial agents. By directly coupling light, heat, and proton dynamics within a single framework, this work establishes a general paradigm for utilizing non-radiative energy to regulate proton-driven photocatalytic reactions.